Cats hate citrus, and it will keep the mof stuff you don't want them on.
Also, doing their business somewhere other than their litter box is very abnormal and generally a sign of mental or physical problems. Kitty is either stressed and upset by something, needs a vet visit, or both. Cats are good at hiding when they aren't feeling well, and if she's acting out now she's either upset and at wits end, or in pretty bad physical discomfort.
Appreciate the advice, but we know. Our cats don't seem to mind citrus, or tin foil, or most of the other things that are supposed to keep cats off of stuff you don't want them on. As for stress or discomfort, like I said she's old. We've taken her to the vet about this but they couldn't help. Near as anyone can tell it's basically the kitty equivalent of dementia. Honestly she didn't respond very well to getting fixed. It's not good to do that to cats later in life but she was originally my in-law's cat and they didn't have her fixed until after she got pregnant and had a litter. That was about 6 years ago and by all accounts her personality radically changed afterward. Supposedly she used to be kind of sweet but when I first met her it was right after and she would hide under the bed all day and growl like a fuzzy black demon.
Eventually it got better, but even after she came out and started being social again she was always kind of stand-offish and hostile, and would act out and pee/poop on things seemingly out of spite. She would specifically wait until something had just been cleaned or we had company over to do it. That part only got worse as time went on. Once she actually climbed up onto my wife's back while she was laying on the bed, hunkered down and deliberately pissed all over her. We've done everything within our capabilities but we don't have a lot of money and can't afford to replace furniture if she wrecks something, and our place isn't big enough to be able to put her somewhere where there aren't any rugs, laundry, or furniture. We've tried picking up the rugs and locking her in the bathroom with her food/water/litter box but she just howls and bangs at the door until someone lets her out, and again, our place is not big enough to have that going on and be able to sleep--to say nothing of the neighbors complaining. And it's not like a very old, black cat with serious behavior problems is ever going to get adopted.
To be perfectly honest she's always had personality/mental problems, from what I've heard. She was originally a rescue that my mother in-law found abandoned as a kitten at the vineyard where she works. Apparently she was covered in some kind of black, tarry substance--possibly one of the fertilizers or pesticides that they use out there--to the point that when they started washing her they weren't even sure what color of cat she was going to be. I've never gotten a lot of details, but apparently she was troublesome enough as a kitten that they named her "Lucifer", which got changed to "Lucifrina" once they realized she was a girl. This from a family so religious they stopped celebrating
Christmas for a number of years out of concern that the holiday was more rooted in idolatry and old pagan festivals than in reverence to Christ. So that should tell you something. (Yeah, I know, my mother in law is a piece of work--but that's a rant for another time.)
Honestly, I think the last straw was when she clawed up my wife's arm yesterday when she tried to pick her up off the back of the couch. Bottom line. We have one less cat now.
After six years of forced patience and constant trying, it really shouldn't be as hard as it is.